class Hashie::Mash

Mash allows you to create pseudo-objects that have method-like accessors for hash keys. This is useful for such implementations as an API-accessing library that wants to fake robust objects without the overhead of actually doing so. Think of it as OpenStruct with some additional goodies.

A Mash will look at the methods you pass it and perform operations based on the following rules:

Basic Example

mash = Mash.new
mash.name? # => false
mash.name = "Bob"
mash.name # => "Bob"
mash.name? # => true

Hash Conversion Example

hash = {:a => {:b => 23, :d => {:e => "abc"}}, :f => [{:g => 44, :h => 29}, 12]}
mash = Mash.new(hash)
mash.a.b # => 23
mash.a.d.e # => "abc"
mash.f.first.g # => 44
mash.f.last # => 12

Bang Example

mash = Mash.new
mash.author # => nil
mash.author! # => <Mash>

mash = Mash.new
mash.author!.name = "Michael Bleigh"
mash.author # => <Mash name="Michael Bleigh">

Under Bang Example

mash = Mash.new
mash.author # => nil
mash.author_ # => <Mash>
mash.author_.name # => nil

mash = Mash.new
mash.author_.name = "Michael Bleigh"  (assigned to temp object)
mash.author # => <Mash>

Public Class Methods

[](source_hash = nil, default = nil, &blk)
Alias for: new
new(source_hash = nil, default = nil, &blk) click to toggle source

If you pass in an existing hash, it will convert it to a Mash including recursively descending into arrays and hashes, converting them as well.

Calls superclass method
# File lib/hashie/mash.rb, line 65
def initialize(source_hash = nil, default = nil, &blk)
  deep_update(source_hash) if source_hash
  default ? super(default) : super(&blk)
end
Also aliased as: []

Public Instance Methods

[](key)
Also aliased as: regular_reader
Alias for: custom_reader
custom_reader(key) { |value| ... } click to toggle source

Retrieves an attribute set in the Mash. Will convert any key passed in to a string before retrieving.

# File lib/hashie/mash.rb, line 85
def custom_reader(key)
  value = regular_reader(convert_key(key))
  yield value if block_given?
  value
end
Also aliased as: []
deep_merge(other_hash, &blk) click to toggle source

Performs a #deep_update on a duplicate of the current mash.

# File lib/hashie/mash.rb, line 143
def deep_merge(other_hash, &blk)
  dup.deep_update(other_hash, &blk)
end
Also aliased as: merge
deep_merge!(other_hash, &blk)
Alias for: deep_update
deep_update(other_hash, &blk) click to toggle source

Recursively merges this mash with the passed in hash, merging each hash in the hierarchy.

# File lib/hashie/mash.rb, line 150
def deep_update(other_hash, &blk)
  other_hash.each_pair do |k,v|
    key = convert_key(k)
    if regular_reader(key).is_a?(Mash) and v.is_a?(::Hash)
      custom_reader(key).deep_update(v, &blk)
    else
      value = convert_value(v, true)
      value = blk.call(key, self[k], value) if blk
      custom_writer(key, value)
    end
  end
  self
end
Also aliased as: deep_merge!, update
delete(key) click to toggle source
Calls superclass method
# File lib/hashie/mash.rb, line 124
def delete(key)
  super(convert_key(key))
end
dup() click to toggle source

Duplicates the current mash as a new mash.

# File lib/hashie/mash.rb, line 130
def dup
  self.class.new(self, self.default)
end
Also aliased as: regular_dup
fetch(key, *args) click to toggle source
Calls superclass method
# File lib/hashie/mash.rb, line 120
def fetch(key, *args)
  super(convert_key(key), *args)
end
has_key?(key)
Alias for: key?
include?(key)
Alias for: key?
initializing_reader(key) click to toggle source

This is the bang method reader, it will return a new Mash if there isn't a value already assigned to the key requested.

# File lib/hashie/mash.rb, line 103
def initializing_reader(key)
  ck = convert_key(key)
  regular_writer(ck, self.class.new) unless key?(ck)
  regular_reader(ck)
end
key?(key) click to toggle source
Calls superclass method
# File lib/hashie/mash.rb, line 134
def key?(key)
  super(convert_key(key))
end
Also aliased as: has_key?, include?, member?
member?(key)
Alias for: key?
merge(other_hash, &blk)
Alias for: deep_merge
merge!(other_hash, &blk)
Alias for: update
method_missing(method_name, *args, &blk) click to toggle source
# File lib/hashie/mash.rb, line 194
def method_missing(method_name, *args, &blk)
  return self.[](method_name, &blk) if key?(method_name)
  match = method_name.to_s.match(/(.*?)([?=!_]?)$/)
  case match[2]
  when "="
    self[match[1]] = args.first
  when "?"
    !!self[match[1]]
  when "!"
    initializing_reader(match[1])
  when "_"
    underbang_reader(match[1])
  else
    default(method_name, *args, &blk)
  end
end
regular_dup()
Alias for: dup
regular_reader(key)
Alias for: []
replace(other_hash) click to toggle source
# File lib/hashie/mash.rb, line 181
def replace(other_hash)
  (keys - other_hash.keys).each { |key| delete(key) }
  other_hash.each { |key, value| self[key] = value }
  self
end
respond_to?(method_name, include_private=false) click to toggle source

Will return true if the Mash has had a key set in addition to normal respond_to? functionality.

Calls superclass method
# File lib/hashie/mash.rb, line 189
def respond_to?(method_name, include_private=false)
  return true if key?(method_name) || method_name.to_s.slice(/[=?!_]\Z/)
  super
end
shallow_merge(other_hash) click to toggle source

Performs a #shallow_update on a duplicate of the current mash

# File lib/hashie/mash.rb, line 168
def shallow_merge(other_hash)
  dup.shallow_update(other_hash)
end
shallow_update(other_hash) click to toggle source

Merges (non-recursively) the hash from the argument, changing the receiving hash

# File lib/hashie/mash.rb, line 174
def shallow_update(other_hash)
  other_hash.each_pair do |k,v|
    regular_writer(convert_key(k), convert_value(v, true))
  end
  self
end
underbang_reader(key) click to toggle source

This is the under bang method reader, it will return a temporary new Mash if there isn't a value already assigned to the key requested.

# File lib/hashie/mash.rb, line 111
def underbang_reader(key)
  ck = convert_key(key)
  if key?(ck)
    regular_reader(ck)
  else
    self.class.new
  end
end
update(other_hash, &blk)
Also aliased as: merge!
Alias for: deep_update